1. Field of the Invention
This invention relates to an information signal reproducing apparatus, and more particularly, to an information signal reproducing apparatus in which, from the recording medium on which composite signals formed by superimposing a plurality of pilot signals having different frequencies from one another successively on information signals in a one-to-one relationship with the tracks were recorded, and from which said information signals are reproduced.
2. Description of the Prior Art
In the art of video tape recorders (hereinafter called VTR) of the kind in which video signals are recorded while video tracks are formed obliquely with respect to the longitudinal direction of the magnetic tape, or of the so-called helical scan type, depending on the recording format for control of tracking in reproduction, there are the following two types: One being that of which a control signal (hereinafter called CTL) is previously recorded in the vicinity of the edge of the tape (which is hereinafter referred to as "CTL" type), and another type of which each of four pilot signals of different frequencies is recorded in a video track, respectively, in superimposing relation to the video signals (hereinafter referred to as "4f" type). Both types of VTRs have been commercialized.
Further, in the art of VTRs of the aforementioned CTL type, a VTR having a low speed (LP) mode in which the tape speed during recording is reduced to a fraction of that of the standard tape speed and the video track pitch is made narrower, thus resulting in a great increase in the total recording time for the same tape cassette, has already been commercialized.
Needless to say, during reproduction, the video tape which was recorded by a VTR of this kind, or having the standard recording mode (SP mode) and LP mode, must be moved at the same speed as when it was recorded. The reproduction apparatus using the CTL type recording media is constructed such that the tape is first moved at a certain speed to reproduce the CTL from which the tape speed that was used during recording is determined, thereby matching the running speed of the tape during reproduction with the speed at which the same tape was recorded.
In the aforementioned 4f type of VTRs, although able to be recognized as having the high density recording technique, because the aforementioned CTL was not recorded, a signal which directly represents the video track pitch cannot be obtained. Therefore, the speed at which the tape was moved during recording cannot be automatically examined. For this reason, in the present state of the art, reproduction apparatuses adapted to be used with the 4f type of recording media generally have only one moving speed for the tape.